Sofa



FIG. 1 is a perspective view from the front side of a sofa in accordance with the present design;

FIG. 2 is a perspective view from the left side thereof; and,

FIG. 3 is a perspective view from the rear thereof.

The bottom of the sofa is not illustrated and forms no part of the present design. 

The ornamental design for a sofa, as shown and described. 